918
FXUS62 KRAH 061950
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
350 PM EDT Fri Jun 6 2025

.SYNOPSIS...
A series of mid and upper-level disturbances will overspread and
interact with a frontal zone that will settle into and stall over NC
this weekend through early to mid next week.

&&

.NEAR TERM /TONIGHT/...
As of 230 PM Friday...

Diurnal cumulus clouds are beginning to develop across much of the
forecast area, with the primary exception being the US-1 corridor
southwest of Raleigh. Coverage of showers is very isolated in
western North Carolina right now, but coverage is likely to increase
as scattered convection along the Appalachian Mountains moves east.
Overall, it seems as if the models have backed off slightly on the
areal coverage of showers and storms locally, and the new forecast
only has a small portion of the Triad with chance pops, with slight
chance pops barely making it into the Triangle. The 12Z NAM seems to
line up fairly well in coverage with the latest version of the time-
lagged HRRR, which shows the greatest chance for thunderstorms
across the Triad between 8pm and 12am. Any precipitation should come
to an end shortly after midnight. As of the 12:30pm SPC Day 1
Convective Outlook, the marginal (level 1 of 5) risk lines up pretty
well with where the forecast will include some chance for
precipitation, with damaging wind the primary threat. With decreased
coverage of storms, this essentially decreases the chance for severe
weather; however, model soundings show the potential for anywhere
between 1500-2500 J/kg of MUCAPE, so there will be plenty of
instability for any storms that do develop to work with, despite
minimal shear. It will be a muggy night with high dewpoints and lows
ranging from the mid 60s to the low 70s.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 350 PM Friday...

* Hot and humid this weekend, with scattered (to locally numerous in
  clusters) thunderstorms during the afternoon through evening

Sat and Sat night: A srn stream impulse now over ern KS/wrn MO and a
preceding convectively-amplified mid-level trough will move
generally ewd across the OH and TN Valleys tonight, then across the
srn Middle Atlantic, with an accompanying belt of 30-40 kts of mid-
level, wly flow, on Saturday. An MCV associated with the latter, now
over srn MO, will likely have reached swrn VA/sern KY by 12Z Sat,
based on the latest model guidance. CAMs, aside from the outlier and
dry FV3, suggest this feature will prove most influential in the
development of deep convection across cntl NC during the afternoon.

At the surface, a frontal wave, probably deepened beneath the
aforementioned MCV, will redevelop within a lee trough across the
srn Middle Atlantic Piedmont and move east across NC and/or srn VA
through the day. A weak front, possibly strengthened/reinforced by
outflow, will settle slowly swd to sewd across cntl NC through Sat
night.

There will likely be considerable mid/high-level convective debris
cloudiness over cntl NC, especially the nrn half, during the
morning, with thinning and clearing through midday. A few sprinkles
or light rain from the associated decaying, upstream convection may
accompany those mid-level ceilings. Strong heating into the mid/upr
80s north to lwr 90s south, of an unseasonably moist airmass
characterized by surface dewpoints in the mid 60s to around 70 F,
will follow and yield a moderately unstable and weakly inhibited
airmass by early afternoon. As previously noted, most CAMs indicate
convection will develop and concentrate ahead of the MCV, perhaps by
midday-early afternoon over the Foothills and wrn Piedmont, then
spread ewd across cntl NC in clusters, and perhaps transient
supercells given the adequate mid-level flow and effective shear.
Damaging wind gusts, and perhaps some severe hail with the most
intense updrafts, will pose the primary hazards. Convective coverage
and intensity should diminish behind that convection through the
evening, though a slight chance of a shower/storm will persist
overnight, given the presence of the outflow/front and low-level
convergence. Unseasonably mild and muggy lows will be in the mid 60s
to lwr 70s.

Sun and Sun night: A shortwave perturbation now digging across the
Pacific Northwest will progress into the mid MS Valley by 12Z Sun,
then pivot across the OH and TN Valleys Sun and the Middle Atlantic
and Carolinas Sun night. The right entrance region of an associated,
~75 kt, swly upr-level jet, atop continued 30-40 kts of mid-level
flow, will overspread cntl NC during the afternoon and evening. A
weak, outflow-reinforced front will retreat nwd into VA ahead of
another frontal low, possibly amplified by upstream convection/
latent heating, forecast to track across the srn Middle Atlantic.
Like Sat, a trailing, outflow-reinforced boundary will probably
settle across cntl NC late Sun and Sun night.

Mid/high-level cloudiness, both from upstream convection and related
to the parent shortwave trough/jet, may be more extensive than Sat
and consequently keep high temperatures slightly cooler, especially
over the Piedmont. It will nonetheless remain hot and humid, with
highs in the mid 80s to lwr 90s. Convection will probably again
develop over wrn NC and grow in coverage and intensity as it moves
into a moderately unstable airmass over cntl NC, supported on the
larger-scale by the aforementioned trough/jet. Shear profiles will
again be supportive of both transient supercells and also clusters
or a broken line, all capable of damaging wind gusts and hail.
Similar to Sat night, a slight to small chance of convection will
linger overnight, especially during the evening, with unseasonably
mild and muggy lows once again in the mid 60s to lwr 70s.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 150 PM Friday...

An upper level low over the Upper MS valley on Monday will progress
east through the work week before weakening and lifting to the NE by
Wednesday. On Thursday, an upper level ridge with dry air will build
across the Great Plains and then over the eastern US by Friday. At
the surface, multiple frontal passages will move across the Mid-
Atlantic region bringing daily chances of showers and storms through
the workweek.

Monday looks to be mainly dry across the region with a slight chance
of showers and storms beginning in the afternoon along and east of
the US1 corridor. The rain chances expand across the entire CWA
overnight and into Tuesday as a surface trough moves across the
region. With that, the best chance for precip during the workweek
for the entire CWA will be Tuesday afternoon and evening. Long range
models are showing plenty of instability Tuesday afternoon and
evening along with an abundance of moisture. I would expect strong
to severe storms could be possible Tuesday afternoon and evening
ahead of the main frontal passage. The front will begin to move
across the region early Wednesday but some models suggest it
stalling along the Piedmont/Coastal Plain region for a few days. If
this does occur, expect shower/storm chances to continue (mainly in
the afternoon/early evenings) through the work week.

Temperatures will be in the upper 80s to low 90s next week. It will
feel muggy all week with dew points in the upper 60s to low 70s.
Heat indices on Monday will be in the mid to upper 90s in the
southeastern counties.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
As of 140 PM Friday...

TAF period: There is high confidence in dry VFR TAFs at RDU/RWI/FAY,
while there is less confidence in the INT/GSO TAFs due to the
potential for afternoon/evening convection. As of 17Z, a lone
thunderstorm had developed in the NC mountains and was heading to
the east. Additional convection remains further to the west across
the WV, KY, VA, and TN mountains, and it is this convection that
will provide the chance for showers at INT/GSO this afternoon and
evening. Slightly delayed the timing of the PROB30 groups for
thunderstorms at both sites based on the timing of the latest HRRR,
but feel that IFR conditions remain possible. Any scattered showers
should come to an end by late tonight. Another round of
showers/storms could approach INT/GSO by 18Z Saturday, but
confidence was not high enough to include in this set of TAFs.

Outlook: Additional afternoon/evening showers and thunderstorms are
likely both Saturday and Sunday with an approaching cold front.
After a bit of a lull on Monday, showers and thunderstorms will be
possible again Tuesday and Wednesday. In addition, depending on how
much rain and where showers/storms occur each day, boundary layer
saturation could result in areas of morning fog/stratus at any
terminal.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...CA
AVIATION...Green